Heretofore one generally accepted method of breaking up a roadway or concrete was the use of jack hammers employed by a number of men working on a road surface. Often the jackhammer would engage the reinforcing bars and damage them to cause a rapid corrosion of the reinforcing bars. Often the reinforcing bars found embedded within the concrete required sandblasting for cleaning purposes to remove scale and corrosion in order to condition the bars to form a strong bond for a fresh application of concrete. The use of jackhammers created undesired cracks in adjacent concrete and large amounts of airborne dust were created.
As time went on various apparatuses were provided for breaking up concrete of a road bed which employed fluids such as disclosed in U.S. Pat. No. 4,081,200, dated Mar. 18, 1978 entitled "Method and Apparatus to Remove Structural Concrete". In devices of this nature which employed the use of water there was the difficulty of providing water under sufficient pressure and velocity to provide the cutting and breaking up action necessitated in order to commercially remove structural concrete from a road bed at the same time without damaging the related reinforcing bars and without damaging adjacent good concrete.
Another pressure water cleaning device for floors and gratings is disclosed in U.S. Pat. No. 4,219,155 of Aug. 26, 1980, assigned to the assignee of record, where pressurized water in a pattern is applied to a surface for cleaning purposes as it moves over the surface. Other prior art patents for cleaning road ways and for breaking up concrete using pressurized water or other forces are disclosed in the accompanying Information Disclosure Statement.